ADA parking lot compliance

For a typical California parking lot, compliance comes down to these elements, each with its own requirements under the 2010 ADA Standards and California Building Code Chapter 11B.

• The right number of accessible spaces, including van-accessible spaces
• Stalls and access aisles of the required size
• Stall and aisle surfaces no steeper than 1:48 (about 2 percent) in any direction
• Required signage at each stall and, in California, at the lot entrances
• Curb ramps with detectable warnings (truncated domes)
• An accessible route from the stalls to the entrance

California properties have to meet both. The ADA is the federal baseline; Chapter 11B is the state code and asks for more in several places, including wider stalls, more detailed markings and tow-away signage at lot entrances or beside the accessible stalls. Where they differ, the stricter rule applies.

We're a paving and concrete contractor, not a CASp inspector. A CASp or the building department decides whether a property complies, and nothing here is legal advice.

The minimum depends on the total number of spaces in each parking facility. At least one in every six accessible spaces must be van-accessible, and medical facilities need more.

• 1 to 25 total spaces, 1 accessible space
• 26 to 50, 2 accessible spaces
• 51 to 75, 3
• 76 to 100, 4
• 101 to 150, 5
• 151 to 200, 6
• 201 to 300, 7
• 301 to 400, 8
• 401 to 500, 9
• 501 to 1,000, 2 percent of the total
• Over 1,000, 20 plus 1 for each 100 spaces (or fraction) over 1,000

Stalls and access aisles can be no steeper than 1:48 in any direction. It's the requirement stalls fail most often, and it's hard to see by eye. Asphalt settles over time, so a stall that was fine when built can drift out of tolerance. We check slope with a digital level.

Fresh paint won't fix a stall that's out of slope. We remove and rebuild the stall area in asphalt or concrete at the correct grade, then stripe it. In California, car stalls are at least 108 inches wide and van stalls at least 144 inches (or 108 inches with a 96-inch aisle), each with an access aisle at least 60 inches wide.

Curb ramps can be no steeper than 1:12, with a level landing at the top and a truncated dome warning surface at the bottom. Older ramps often fall short: too steep, set inside an access aisle, or with a lip where they meet the asphalt.

The route from the stall to the entrance has to be continuous, firm and within slope limits, with changes in level no more than 1/4 inch, or 1/2 inch if beveled. A broken panel or a lip at a threshold can interrupt it, which is why ADA work usually involves both asphalt and concrete.

Each stall needs the symbol of accessibility, a hatched access aisle marked NO PARKING, and a sign mounted high enough that a parked car doesn't hide it. Van stalls need a van-accessible designation, and California adds tow-away signage at each lot entrance or beside the accessible stalls. These are the parts that wear out fastest, and the simplest to put right; see signage and wheel stops.

Restriping or resurfacing a lot brings accessible parking under the current standard, and clears the old layout, which makes it the practical time to correct stall count, slopes and ramps.

A Certified Access Specialist (CASp) inspects the site and reports on what needs to change, and the report carries procedural protections under California law. We work from CASp reports regularly: we walk the site with you, price the corrections, help with permits and build the work. If you don't have a report yet, we can put you in touch with a CASp.